Suspension of disbelief is what one does when confronted with a situation crafted for enjoyment but not really realistic. It is not temporary. If the situation is too blatantly false then the suspension fails and the idea is rendered unentertaining.
When you read a story that is fiction, you suspend your disbelief. This suspension is further strained with fantsy, things that can't logically happen in real life. When there is too little explanation to things, or they are too unreal, that is when we state that we can't suspend our disbelief.